


Take My Hand & Show Me Your Heart

by xnemones_graveyard



Category: Ao no Exorcist | Blue Exorcist
Genre: Abandoned Work - Unfinished and Discontinued, Alternate Universe, Civil War, Demon Kings, Demon Summoning, Enemies to Friends to Lovers, M/M, Minor Character Death, Politics, Royalty, Trauma, true name mythos
Language: English
Status: Completed
Published: 2021-01-31
Updated: 2021-01-31
Packaged: 2021-03-18 05:54:43
Rating: Not Rated
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 2
Words: 8,187
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/29113383
Author URL: https://archiveofourown.org/users/xnemones_graveyard/pseuds/xnemones_graveyard
Summary: Rin was taken in by his true father long before Shiro arrived. As a result, Father Fujimoto lived long enough to send his adopted son to a prep school for exorcists, Rin became a prince of Gehenna before he ever learned he was half human, and Yukio’s life didn’t change much. But when Ryuji Suguro summons the ninth King of Gehenna with a generic magic circle and a half-hearted call, there’s a brief moment of confusion that blossoms into a friendship capable of changing the world as they know it.If a demon King falls for a monk, does he make a sound?
Relationships: Okumura Rin/Suguro "Bon" Ryuuji
Kudos: 107





	1. Akeidah - Binding

Bon already knew he wanted to be an Aria. He’s been training his whole life. At the temple, his father taught him verses under the guise of training him as the next clan head, the heir to the temple. Once he learned that demons truly exist and that some of the verses he had hated memorizing could vanquish them, he began to study in earnest.

So he’s not really looking forward to the whole “Tamer Test” thing sensei’s advertising.

“Put a drop of blood on the paper with the magic circle I gave you earlier,” Sensei instructs, pulling an identical one from the fold of his lapel. “Say the first words that come to mind.”

Bon inspects his paper with bored skepticism as Izumo pricks her finger. She says something sailor-moonish and arrogant, waving her two slips around as two white foxes materialize beside her. Izumo smirks as her friend coos over her talent and Sensei congratulates her. Shiemi manages a small Greenleaf demon as well.

“I can’t do it,” Koneko admits, not quite timid.

He looks up at Shima, who gives a shrug and says, “Me neither.”

The two of them turn to Bon.

What the hell? Might as well give it a shot.

His old man would lose his shit if he saw Bon summon a demon, after all. And how kickass would it be to take down Satan with one of his own?

Bon squares his shoulders. He bits his thumb hard enough to bleed and wipes it on the paper. In a loud, slightly awkward voice, he calls, “Uh… Son of Satan, I command thee, to uh, come before me and obey my orders! Or whatever…”

For a long moment, he thinks nothing’s happened. Just as he’s about to lose hope, a playful voice from behind makes him jump.

“At least take me out to dinner first!”

Bon whirls around. He gapes at the young man sitting on the edge of a desk, one ankle crossed over his knee. He’s grinning with wicked sharp canines, pointed ears, and black horns, dressed in a black yukata with grey spiral-patterned trim. His hair is long and dark blue with bangs that frame his face and a loose braid that ends just below his shoulder blades. There are fine golden chains and white gems threaded in. He also has dangling crystal earrings that glitter in the light.

Bon leaps back. The demon disappears in a cloud of blue smoke.

A warm hand with sharp black nails settles on Bon’s shoulder as a low voice murmurs, “Now, that’s not a very nice way to treat a prince.”

Bon yells and whirls around again, but the demon is gone.

“I’m not gonna hurt you,” it laughs, standing in the center of Sensei’s summoning circle. “I don’t even have my weapons! See?”

He holds his hands up, empty. His sleeves slip far enough to reveal the head of a snake wrapped around a yellow flower on the back of one hand and two tattooed bands wrapped around the other wrist.

“What is your name, demon?” Sensei asks, commanding and serious.

Bon is grateful to have the demon’s blue gaze turn away from him as it focuses on his sensei and grins.

“Rin,” the demon answers in a tone that is both dangerous and seductive. “Demon King of Air, ninth son of Satan, and hottest resident of Gehenna.”

He glances over at Bon and winks. He fucking-

Shima grabs his arm as he starts to march forward in order to stop him from giving the ninth King of Hell a black eye.

“A demon King,” Sensei remarks, raising his eyebrows at the demon as he crosses his arms. “Excellent work, Suguro-kun.”

“Oh, Suguro-kun? That’s your name?”

Rin disappears and reappears floating in front of Bon, cross-legged and grinning. Bon jumps back.

“I like it!” the demon announces, beaming.

As if Bon asked for his opinion.

“Go back to hell!” Bon shouts with a right swing.

Rin dodges it with a little, “Oop!” and disappears in another cloud of smoke.

Bon straightens up. Sensei begins speaking again, explaining how demons don’t obey a master weaker than themselves and attack those who lost their confidence. Demon King summon or not, Bon is sure he’ll be fine. Then Sensei demonstrates how to break the magic circle, and class comes to an end.

“Oo, scary,” Rin coos, back to his perch on the edge of the desk. “I like you, Suguro!”

Bon turns to face him as the class begins to disperse. The demon grins, flashing too-sharp incisors and a wicked glimmer in his eyes.

“What’s your deal?!” Bon snarls, getting up in his face with a glare.

Rin leans away with his hands up in surrender, but his self-satisfied smile stays in place. “Maa, maa, there’s no need for violence, Suguro-kun! You called me here in the first place!” he objects, light and almost laughing.

“Whatever.” Bon turns away and tears the summoning paper as he tells his friends, “Let’s go.”

Rin kicks back and grins as he watches them fade away to nothingness.

The heavy, dank atmosphere of Gehenna surrounds him again with the sweet smell of rot. Amaimon is still sitting at their shogi table, staring intently at the pieces.

Rin retakes his seat on the cushion across from his brother with a sigh.

"Curious," Amaimon notes. He touches his chin distractedly as he scans for a move that isn't there. "I can't seem to find a way to win anymore."

Rin grins. "That's because I beat you, brother," he replies with a tilt of his head, leaning back as he rests one hand on his knee. "Care for another round?"

Amaimon looks up at him through round, wide eyes. He sniffs.

"You went to the human realm."

"Yes," Rin concedes with a shrug. "A human summoned me there."

Amaimon's eyes widened. His hand drops. "You?"

Rin nods. "I think he's an exorcist in training, but he looks like a delinquent. I like him."

"You don't have high standards," Amaimon retorts as he begins putting the pieces back in place.

Rin simply laughs and pulls over some of his Assian plum wine. If there's one thing finer than sleeping with an interesting human, it's their wine.

"Another round, brother?" Rin asks, raising his glass.

"And then a spar," Amaimon agrees, clinking his glass to his little brother's. "I still want to learn how you do that fire-slash thing."

"I've told you, it's an attack only I can do," Rin argues, grinning. “Unless you learned how to control wind and fire while I was gone!”

Amaimon curses him in the ancient tongue and places the first piece. His earth demon pet growls in its sleep beside him.

~+~+~+~

"So," Shima starts. "A Demon King."

They're seated at the fountain. Shima is drinking strawberry boxed milk, Konekomaru is biting his lip as he works through some math problems for class, and Bon stares up at the sky to watch the clouds pass, probably reciting verses in his head.

"I hate him," Bon announces.

Shima snorts. He follows Bon's gaze up toward the sky and smiles. He wasn't thrilled to see Bon's new summon either. Between the tattoos and his cocky attitude, Rin doesn’t seem all that reliable. He seems more likely to set Bon off than help him in a fight.

"What I wonder is how you even _summoned_ him," Shima exclaims. He jumps down from his seat and turns to face Bon, throwing his arms out to his sides as he continues. "I mean, shouldn't there be something to stop humans from summoning powerful demons? Why did he listen?"

Bon shrugs.

"Maybe he was bored."

The two of them turn toward the girl who approaches. Izumo steps up to the fountain and flicks her long purple hair over her shoulder, resting her hands on her hips afterward.

"Hah?" Bon retorts, turning toward her with his hands shoved deep in his pockets.

"Well…" She glances away and shrugs slightly. "He's a Demon King. But there's probably not much to do in Gehenna, so…" She digs her toe into the dirt as a blush creeps across her cheeks. With a glance at Bon, she adds, "Maybe he listened just for a change of pace, you know?"

Bon gapes at her for a moment, frowning.

"Maybe he's just not that powerful," Konekomaru pipes up.

He doesn't look up from his homework. Instead, he types something into his calculator and writes down the answer, ignoring when his classmates give him looks.

Bon doesn't like the idea that his summon is weak, but he doesn't like the idea of not being able to control him, either.

Bon slings his bag over his shoulder, calling with a wave over his shoulder, “I’m heading to the library. I’ll catch up with you guys later!”

~+~+~+~

If there’s one thing Ryuji Suguro is good at, it’s studying. He hasn’t lost his honor roll status since he earned it in middle school, and although plenty of that is good luck and skill, it takes hard work, too.

He’s spent countless hours in libraries and cafes, studying for big tests and researching for smaller assignments. Which is why, when a Google search of Rin’s name and title yields few results, he doesn’t lose patience as he’s forced to turn to books. However, the only mentions he finds of Rin’s title, not even his name, are saying the King of Air’s true name and appearance are unknown, that his kin are airborne and bird-like demons, or they’re prophecies about his birth in Assiah, which make no sense. How can a demon be born in Assiah? Especially one of the Kings.

“Damn it!” he exclaims, slamming the latest book shut.

A few other students and teachers send him dirty looks. He hangs his head and slumps back in his chair with a defeated sigh. He stands up and begins going around to put his books back, when an unfortunately familiar voice startles him.

“You’re really obsessed with me, huh?” Rins asks with a grin, eyeing the stack of book in Suguro’s hand.

“Shit!” Bon hisses, startled. “Stop doing that!”

“Doing what?” Rin replies innocently, raising his eyebrows. He disappears and pops up behind him again. “This?”

Bon whirls around to face him, scowling. “Yes! I’m trying to work. How the hell did you get in here, anyway? Isn’t this place warded?”

“Yes,” Rin acknowledges with a nod. “Like paper.”

Bon can feel tension gathering in his head and knows a vein in his temple must be throbbing.

“Why aren’t you in any of the books?” he murmurs, aware that the other students might think he’s talking to himself.

Rin blinks owlishly. “I’m not?”

He plucks one of the books from Bon’s hands and squints at the page he opens to. His clawed finger skims the pages as he flips through, careful not to scratch the book.

“Huh,” he remarks, shutting the book with a soft thud. “I guess I’m still too new.”

“What?”

Rin looks up at him, eyes wide and sincere. He sets the book gently on the shelf, right where it belongs, and speaks softly.

“I’m the youngest of my siblings,” he explains. “Time doesn’t really exist in Gehenna, but I’m only about sixteen by Assian years. The only books you’ll find which mention me by my true name are Reverend Fujimoto’s journal and the Hebrew Bible.”

“Your true name?” Bon echoes.

Rin looks at him and smiles. It’s something sad, understanding, and infuriating at the same time.

“Sorry, that’s a secret!” the demon teases, tilting his head slightly. “Just call me Rin. See ya!”

With a wave and a cloud of smoke, he disappears again.

That’s when Bon ralizes they’re the same fucking age.

“Hey, wait a minute!”

“SHH!”

~+~+~+~

Bon has a small discussion with the school’s director over Rin’s appearance in the library, but he doesn’t appear unsummoned again. In fact, the next time Bon sees the King of Air, he has to summon him to protect Izumo and the other girls.

It's the first day of Okumura-sensei's training camp. Bon, Shima, Koneko and the others have dispersed in the empty dorms to settle in. Izumo, Paku, and Shiemi had talked about taking a bath, but as soon as Bon heard them scream he and Shima came running. Good thing, too.

There’s a naberius in the girls’ bathroom.

“Shima! Get Sensei!” Bon yells, already pulling one of the summoning circles he’s drawn and kept tucked in his pockets-just in case.

Shima nods and makes a run for it. The demon lunges forward, its gaping maw dripping with acidic saliva that burns the ground it touches. It reeks of rotting flesh and snarls incomprehensibly, but Bon chants a prayer that stills it just long enough to summon his demon King.

“Son of Satan, I command thee!” Bon calls, his words practiced and steady. “Come before me and obey my orders!”

The Prince appears in another cloud of smoke, this time dressed in a hakama with a blue and white checkered haori. On his back are two crossed katana, one white and one black. Bracelets of black stone click on his wrist as he places his hand on the hilt of the black one, spreading his feet apart in a fighting stance. His hair isn’t in the braid anymore, traded for a twisted bun with his bangs pinned back.

“Kin of Astaroth, kneel!” Rin commands.

Bon’s chest resonates with the force of his demand. There’s raw power in the Prince’s appearance now, in his voice, in his presence. He seems like a King of Gehenna now.

The naberius recognizes it too and flattens itself to the floor with a whimper.

 _I apologize, Young Master,_ it speaks in the Ancient Tongue, incomprehensible to the young exorcists-in-training. _I was ordered to kill the Okumura._

“By whom?” Rin questions, his voice still echoing with power, demanding an answer.

 _The eye-patch wearer and curser of souls,_ the naberius responds. _His name is Neuhaus._

Rin narrows his eyes. Slowly, he draws the blade of his katana. It reflects the light and warps it. Blue flames alight along its silver edge, striking fear in Bon’s heart. He stands transfixed behind the Demon King and watches as he raises the blade above the beast and whispers something strange, gentle but mangled, before he brings the blade down. It slices through the demon’s flesh swiftly. The beast burns in seconds.

Rin returns his blade to its sheath and turns. His eyes are tired and sad and filled with the same blue fire he just used.

“Are you okay?”

His words swim through Bon’s ears. He can’t seem to move. Rin’s gaze is piercing and blue, and all Bon can think of is that night. The night his father lost everything, the night half the world’s exorcists burned and the scent of seared flesh filled the air like it has now. Bon is shaking, his heart is racing. The panic returns, fresh and raw and suffocating in his throat. He’s on the floor now, trembling. Someone puts a hand on his shoulder and looks into his eyes with a concerned frown. Someone else is calling his name, but her voice is drowned by his fear.

“Suguro,” Rin calls in the same commanding voice as before. “Get it together.”

He jolts back to himself. It’s Rin’s hand on his shoulder and Izumo standing off to the side in her underwear. He blushes and looks away from her. Shiemi is kneeling over Paku, applying aloe to her wounds.

He takes a deep, shuddering breath. Then he allows Rin to help him to his feet.

“Blue flames, huh?” he asks softly, staring at the ashes of the naberius.

Rin watches him silently.

Bon tears the paper without a word and Rin slips away.

“What’s going on here?” Sensei’s voice interrupts as the smoke clears.

Bon turns. Izumo has put on a shirt, thanks to Shima-who appears to have a nosebleed. Sensei is staring at Bon with an expression of alarm and concern, which turns more toward the latter when he sees the look on his student’s face.

“There was a naberius,” Bon explains, as calmly as he can when he still feels shaken.

“Suguro-kun saved our lives,” Shiemi explains, earnest. “He summoned Rin and took care of the demon for us!”

“Izumo, why didn’t you use your summons?” Okumura-sensei asks her, gentle.

“I- I tried, but they- I couldn’t control them.” She looks down as her face turns red.

Yukio turns back toward Bon and his other students.

“Excellent first aid, Moriyama-kun,” he tells Shiemi with a nod. “And Suguro-kun, good work. These three may very well have died without your help.”

Bon nods, numb. As sensei goes on about security concerns and staying in groups, he looks down.

If Izumo’s demons wouldn’t obey her, why was Rin so eager to help? At the sight of blue flames, Bon had a panic attack. It would have been the perfect opportunity to slice through him as he did the naberius. Instead, Rin offered his hand and asked if he was okay.

“Suguro-kun, are you with me?”

Ryuji lifts his head, startled. “Yes, sir,” he answers automatically. “Stay together and be careful. I got it.”

Yukio purses his lips but lets it go. As he turns away, asking his students to follow, Bon sighs.

It’s going to be a long day.

~+~+~+~

Once Suguro explained there was a naberius, Yukio knew who was responsible. There’s only one person at True Cross Academy with naberius summons, and whatever reason Neuhaus has, Yukio intends to find out.

However, by the time he tracks down the Upper First Class Exorcist, a grisly sight awaits him.

Naehaus’s corpse is burned. Not just that, either. He’s fallen from the roof of the dormitory, and the acid burns are those from his own summons. The eyepatch over his left eye has slipped, revealing a scarred, gaping hole where his eye used to be.

Yukio braces himself on the wall, too busy throwing up his lunch to notice the dying flicker of blue flame on the roof above.

~+~+~+~

Bon can’t stop thinking about him. Why didn’t Rin attack? Why did he appear as though he were prepared for the fight in the first place, when he showed up unarmed and immature the first time Bon summoned him? What’s his deal?

Meanwhile, Rin splits his time between Gehenna and Assiah, training his abilities and his mind through meditation and training with his brothers, Amaimon, Astaroth, and Samael. Occasionally, he and his sister Egyn discuss Gehennan politics and the best way for demons to live more permanently in Assiah-both condemning their father’s method of destroying humanity as archaic and implausible-until their brother Iblis challenges them to a spar and gets knocked out in an instant by the hilt of Rin’s sword and the side of Egyn’s hand. He was in the middle of one of these sessions with Egyn when Bon summoned him to defend him.

He discovered Neuhaus’s target to be Yukio Okumura and confronted the exorcist in the rain. Neuhaus called Yukio a “dirty son of Satan” before he called his summons to fight Rin himself, but no human can better control demons than a Demon King. Rin watched Neuhaus’s dogs tear him apart and burn his flesh before Rin himself drove the crazed man off the roof and burned the tormented summons to finally put them out of their misery.

The act of turning living beasts into demons is a cruel and inhumane practice.

As luck would have it, Yukio Okumura stepped out to discover the body as the dogs burned. Rin watched him for a moment. His exorcist uniform is clean and precise; well cared for. He seems like an honest man, with no hint of demonic traits or power. Yet, according to Neuhaus, he’s Rin’s brother.

Rin decided to do some digging. He found Reverend Fujimoto’s church and nearly frightened the poor priests cleaning the windows out of their skins. Rin kept his hand tucked into the fold of his yukata and his weapons sheathed as he confronted the priest.

“Who is Yukio Okumura.”

To his credit, Shiro Fujimoto only raised an eyebrow and turned, a smile on his face.

“That depends,” he replied calmly, steeling himself. “Who are you?”

Rin narrowed his eyes. “You know who I am,” he retorted. “Why did you keep him from me?”

“Why?” Fujimoto’s eyes hardened. His grip on the pew beside him tightened. “Because he’s human.”

“Yes,” Rin agreed, startling the priest. “He’s only half-human by blood, but his heart is a man’s. So why,” Rin growled through gritted teeth, “did you keep my twin brother secret?”

Beneath his words are the hidden questions Rin has wondered all his life. _Why didn’t you take me too? Why did I have to be raised by demons?_

“Because Satan got to you first.”

Rin startled.

“Believe me, Rin,” Father Fujimoto said, moving forward with his hand outstretched. “If he hadn’t, I would have taken you both in. I haven’t told him. I wasn’t sure-”

“You weren’t sure of what?!” Rin snarled. He clenched his fist at his side as the air around him began to heat. “That I would protect him?! He’s my little brother!”

The priest opened his mouth to speak, but Rin turned on his heel and stalked out. The sacred ground hardly even made his feet itch. He left, returned to Gehenna where he had been sparring with Iblis who had paused to inspect her long nails, bored. She looked up when he returned and startled at the expression of raw fury on his usually smooth features. She sprang to her feet, but he dismissed her with a wave and went to talk to their father.

Satan confirmed it. Rin’s mother is dead. Yukio is his human brother, left for dead in the snow when the demons sent for Rin found him.

That was the moment Rin lost his faith in his father at last. Some of his older brothers had already turned against him, seeking peace in Assiah for themselves. But Rin has a grander vision. Most demons don’t disturb humans unless provoked. If there’s a way to create a bridge between worlds and foster a peaceful agreement, there’s no reason for demons to be confined to the impurity of Gehenna forever. There is no reason for his own kind to suffer in a place that turns them cruel.


	2. Bitachon - Trust

Rin knows that if his plan is to succeed, he needs the support of as many of his siblings as he can muster. If possible, he needs human exorcists on his side as well. Their input is valuable, having made a career out of killing demons with tools demons can’t touch, and as such, their knowledge and aid would be immensely useful.

Lucifer and Astaroth will be the most difficult to convince. If it comes to blows, Rin needs to be able to defeat them; for the sake of Gehenna and Assiah alike.

Which is why he needs Suguro to trust him.

He’s started keeping an eye on his human “master”; as if any human could control him. Sometimes he pops into the human realm to find Suguro slumped over a textbook and sets it aside to help him into bed. Others, he watched from a rooftop as Suguro and his friends eat lunch, often accompanied by Eyebrows and the blonde girl in the yukata. Eyebrows watches Suguro with a look Rin knows all too well. He tries to ignore his jealousy by covering it with amusement, but his annoyance is still there as she leans over to touch his arm or laughs a bit too hard at something he says.

Rin doesn’t like sharing. He’s not used to rejection, either. Luckily, Suguro doesn’t seem too interested in Eyebrows. Maybe he’s just oblivious, or maybe he just doesn’t care.

In any case, it’s worked out in Rin’s favor. He’s been the target of a jealous woman’s rage before, and it’s not fun.

When the exorcists begin their official training camp in the woods, Rin is wary. He greeted the King of the Forest, but there’s something in the air and too many demons in the area for this to go too well. Plus, Suguro’s been acting strange since he learned of Neuhaus’s death. Before the dormitory test, he delved into research into Hebrew gods and summoning circles. However, he’s put away his books and has just been practicing sutras. It’s almost as if he doesn’t plan on summoning Rin ever again.

Rin’s a little worried.

Usually, the rule for demons is not to come unless called. They don’t defend their masters unless summoned, and they certainly don’t watch from a safe distance and _hope_ to be summoned. And yet, that’s exactly what Rin is doing.

“What in Father’s name are you doing, Rin?” Sam-who calls himself Mephistopheles here-inquires from his floating throne, holding a closed umbrella over his shoulder.

Rin doesn’t answer. The students are being briefed on their task for the evening. Rin notes with some relief that they’ve set up a proper magic circle to defend them against all the fauna in the woods, but it would be child’s play for him to tear through.

“This is a rather unhealthy obsession,” Egyn notes, appearing at Rin’s side on the tree branch he’s perched on. “Lucifer is beginning to worry about you.”

“Yeah, right,” Rin scoffs.

Their eldest brother hardly pays any attention to Rin, and they’ve never actually spoken.

“Does he really interest you that much?” Mephistopheles asks, following his gaze to the humans. “Has he been brushing you off?”

“Shut up,” Rin retorts. He leans forward as the students start to split and move out in different directions.

“There he goes,” Egyn sighs, somersaulting into the air with her white robes and blonde hair billowing out around her like she’s in the water she controls. “It’s no use talking to him when he’s like this, Sam. He’s not going to listen.”

“You’re right,” he sighs with a shrug. “I’m afraid I have some pressing business to attend to, so I must be going.”

“As do I,” Egyn replies, and both of them disappear in a pop.

Rin continues to watch the humans. A swarm of bugs attack each of them in the darkness. Blondie is the only one who seems to have trouble dealing with them, but once Suguro dispels his cluster, he rushes to her aid. A few of their other classmates to, too.

Baldie found the first lantern. It seems like the students have finally realized it’s not actually an individual exercise, but one to test their teamwork. When they finally arrive in front of the lantern, Suguro recognizes it as the demon it truly is.

Rin bites his thumb and smiles. “Now then, what will you do?” he muses.

Clearly, the best way to move the lantern is to summon him. But despite Baldie’s suggestion that he do just that, Suguro refuses. Instead, he insists he can push and chant at the same time, as long as Baldie helps.

Rin sighs in disappointment. He floats down to the ground below and begins to make his way across the forest toward them, lighting his way with the palm of his hand. The demons of the forest chitter and bow away before him, eyes following the small blue flame dancing in his hand.

As soon as the rumble of the wagon comes within earshot and he catches a glimpse of firelight, Rin extinguishes the flame.

~+~+~+~

“Hey, what was that?!” Shima yells over the roar of bugs tearing through the air above their heads.

Bon can’t risk pausing in his chant, so he settles for looking off into the woods Shima was staring at and frowns.

“Nevermind that!” Shiemi howls, trying to shield her face.

“Right,” Shima agrees, twirling his K’rik with a little more vigor.

Bon’s lips move through the sutra automatically, his thoughts on nothing but the next word and moving the _damn_ lantern, far too heavy, and Konekomaru was the only one with free hands but he’s _weak_ , they’re both _weak_ , and if he’d just been able to swallow his pride and his fear and summon the _damned son of Satan_ then _maybe_ -

Enough. This isn’t the time to get distracted, and anger just burns up his energy as fast as the peg lantern consumes its prey.

Not that he has much of it anyway.

He hasn’t been sleeping well. Every time he closes his eyes, he sees blue flames. Whatever Rin’s thinking, whatever the reason he didn’t attack Bon then doesn’t matter. He’s not going to give the demon a chance. He’s been training to be an Aria for years now; just because he has a demon familiar doesn’t mean he has to use him.

But he’s weak. He’s tired, and it’s getting harder to remember the sutra. His tongue is starting to feel heavy and thick in his mouth, and finally, dreadfully, he slips on the words.

The peg lantern comes to life with a roar.

Moriyama screams. Bon stumbles as the weight of the cart pitches and Konohamaru leaps away. Bon and Shima grab Shiemi and pull her off to put her behind them. The bugs tear off the tag and the lantern lurches forward after them.

Bon yells at them to run, seeing their only chance now to be leading the lantern back to camp.

"I'll hold it off!" Bon shouts, his hands already forming a prayer sigil.

He begins chanting as Shima pushes Konekomaru and Shiemi to run. They don't need to be told twice. Bon watches it struggle between going back to sleep and chasing after them as Shima tries to fight off the bugs with renewed vigor, trying to make the lantern run out of fuel.

It's no use.

Then cold, sharp-tipped fingers wrap around his throat from behind and Bon's words die in his mouth.

"Bon!" Shima screams.

"Don't mess with my little brother," a deadly, tilted voice warns in his ear.

Something scratches Bon's neck. His vision starts to narrow and he starts sweating worse, his heart racing.

"Shit…"

He hits the ground hard.

Dazed, he watches as the lantern runs past them, chasing Shiemi, but a swath of blue flames stop it in its tracks. It shivers and bows before someone, someone angry, with two swords cloaked in blue fire.

He lifts his head as the lantern's flame dies. Bon's heart jumps into his throat as piercing, furious blue eyes lock onto the demon standing in front of Bon. Its weird, pointed shoes turn outward. As Rin stalks forward, it takes a step back and starts to explain that he was trying to _protect_ Rin, there's no need to get violent. Why is he getting so worked up over one little human? Is he really that interesting?

Rin slices his katana through the air. Bon feels the heat wave that cuts through the air above him, prompting the other demon to trip over him in an attempt to scramble away.

"Rin!" the demons calls, fear making his voice shake. "Stop this! He's just a human, you can find other ones! He's not even that attractive, come on!"

"I need him," Rin growls, primal and vicious.

"R… in," Bon pleads, reaching out toward him.

The Demon King looks at him. His expression immediately softens, turned from cold fury to gentle in half a second.

"It's okay, Suguro. Leave it to me."

He springs toward his brother with a war cry and Bon shuts his eyes as the other lets out a terrified shriek.

Maybe, it's okay to let sleep take ahold of him just this once.

~+~+~+~

By the time Rin teaches Amaimon that he doesn't need to be protected from his human, the human in question is down for the count. Rin races back to him, leaving his older brother singed and exhausted in the bushes.

Suguro is lying on the ground, pale, sweating, and breathless.

"Seriously?!" Rin exclaims, examining the nasty, greenish cut Amaimon left on his human’s neck. "Fuck!"

He saw the way Suguro reacted to his fire before. He's scared of it. Most creatures are; his unholy blue flames are a surefire death for anyone.

But not if he's careful.

Rin places his hand over the wound and shuts his eyes. His focus is impeccable as his flames lick their way into the cut and burn away the demonic poison. He's glad it's plant-based. Otherwise, this might not work as well.

"Bon!" another human voice yells.

Pinky comes running toward them just as Rin finishes dealing with the last of the poison and sits up.

Bon opens his eyes. He focuses blearily on Rin, blinks a few times, and groans, draping his arm over his eyes.

"You should have called me," Rin tells him solemnly. "If I hadn't been here, you'd all be dead."

"How did you get here then, if Suguro-kun didn't summon you?" Blondie asks, jogging toward them as well with Baldie right behind.

"Now that would be giving away my secrets!" Rin beams.

Bon finally lets his arm drop and turns his head towards Rin without opening his eyes.

"Why did you save me?" he asks softly.

Rin looks at him and his smile falls. He sheaths his swords and takes a seat on the ground with a heavy sigh, crossing his legs.

“I would rather get along with humans than have to fight you,” he admits honestly.

Bon sits up to listen.

“Gehenna isn’t an awesome place,” Rin continues. “I know my father and some of my siblings want to take over Assiah, but that isn’t- It won’t work. He’s too arrogant to realize how strong you are.”

“And you’re not?” Shima asks dubiously, raising an eyebrow.

Rin looks up at him and says, “No. I’m just as strong as my eldest brothers, despite being the youngest and half-human.”

Bon inhales sharply. “The King of Air born of Assiah,” he breathes, as if quoting a book. He stares, wide-eyed, at Rin. “So it’s true.”

Rin smiles at him again, but this time there’s something sad and serious to it. “Gehenna turns demons against each other, forcing us to fight and kill each other to survive. If we can live in Assiah with the food and resources we need, the wars would end and my brothers and I could become the Gods we once were.”

“You mean you used to be more powerful?” Baldie asks breathlessly.

Rin snorts. He bows his head. “Not me, but my brothers. We were given physical forms by humans, and our power relies on our names. As long as we’re feared and respected, our power grows. But if we’re not…” Rin lights a flame between his fingertips and extinguishes it between them. “We disappear.”

He looks up. Suguro and the humans are staring at him, eyes wide and almost afraid.

“Come on,” Rin exclaims suddenly, bounding to his feet with a good, practiced false grin. “Let’s get this lantern back to your sensei!”

~+~+~+~

Yukio thought about charging into the forest alone the moment he saw the blue flames. It was Shiro’s hand on his shoulder—Dad came at Yukio’s request to help oversee the test—and the memory of Suguro coming to him during the Exwire test to ask about the King of Air and blue flames, that makes him pause. Yukio is glad for it too, when almost all of his students and one demon return with one of the peg lanterns in tow.

He releases a sigh of relief that earns a laugh and clap on the back from his dad.

“Now you know how I felt every time I sent you off to fight demons,” Shiro tells him lowly.

“Nice work, everyone!” Yukio calls to his students.

He steps toward the group and eyes the Demon King pulling the cart, dressed in traditional robes with long dark hair. The demon eyes him with suspicion and something akin to nostalgia as he approaches.

Izumo leaps to her feet to ask Suguro if he’s alright. The demon clicks his tongue and glares at her, but otherwise doesn’t react even when she puts her hand on him and says it was too much of a risk summoning him, why did he do it, is he an idiot?

Suguro looks at the demon calmly and tells her, “I didn’t. He saved our asses though.”

“Don’t get used to it,” the demon mutters.

“Suguro-kun, is this your familiar?” Yukio asks.

“Yes, Okumura-sensei,” Suguro replies calmly, turning away from him.

Yukio notices with a start that the demon walks calmly across the circle as if it weren’t there. He sets down the cart and stalks toward Shiro. Yukio glances back to find his father watching the demon with a solemn expression, and that’s when Yukio realizes something is wrong.

“Did you tell him yet?” Rin demands, stopping a few feet in front of the priest.

Shiro raises his chin slightly, inhaling deep.

“No.”

"He deserves to know, _Father_ ," the Demon King growls, but Shiro doesn’t flinch. Rin turns and, to Yukio’s surprise and fear, makes a beeline straight for him.

“Rin!” Shiro calls after him, “You know what this could cost him!”

“Yeah, I do." The demon snarls and grabs Yukio by the collar. Instead of biting his head off like Yukio half expects, he leans in and growls, “Ever wondered why you could always see demons, Yuki-chan? Why the scent of blood makes your stomach churn and the sweet smell of rot is so familiar? Ask your old man who your real father was, jerk."

He releases the young exorcist and continues back toward his summoner. Yukio allows himself to breathe, but the demon’s words stick in his mind. He turns back toward his father, lips parted to ask a question but the words die on his tongue at the sight of Shiro’s expression. Yukio’s never seen him look that sad and guilty before.

“I have to go,” Rin tells Suguro softly. “Take care of yourself, Suguro.”

“Bon,” he corrects.

When Rin shoots him a questioning stare, Suguro bows his head and continues.

“It’s… Bon. Call me Bon. After all,” he says, meeting the demon’s eyes with a nervous smile, “we’re friends, ain’t we?”

Rin smiles back, soft and fond. “Yeah,” he replies with a nod. “Yeah, we are. See ya around, Bon.”

With a slight bow, he disappears in a cloud of blue smoke.

Yukio tries to pretend he doesn’t notice the fact that his student is clearly in some sort of relationship with his demon summon and turns back to his class for a debrief. Only at the end does Konekomaru see fit to mention that Amaimon, King of Earth, decided to attack them.

Yukio is starting to wonder why he ever thought this job would be a good idea.

~+~+~+~

Shiro would be lying if he said he weren’t afraid. He’s sitting at a table in a restaurant near True Cross Academy with a bottle of hot sake when Yukio comes in to take the seat across from him.

Shiro finishes his cup and looks his adopted son in the eye. Yukio’s eyes hold all the questions he must be burning to ask, but instead he simply greets his father and asks how his day has been. They order dinner and chat, sharing opinions and suggestions about Yukio’s students and never once mentioning the Demon King, Rin.

But Rin was right. Yukio deserves to know.

As they finish their plates and conversation slow, Shiro sets down his empty cup with a heavy sigh. Yukio’s eyes follow the motion of his fingers as they pull a photograph from inside his coat and presents it on the table. Yukio looks down and breathes in sharply.

The photograph is from the day Shiro found him in the snow. Yukio was wrapped in a blanket in the cold, stiff embrace of a dead woman. Beside him was an empty blanket, singed at the corner with melted footprints that definitely weren’t human.

“Father, what is this?”

“I found you like this,” Shiro admits solemnly, lacing his fingers together in front of his mouth with his elbows propped on the table. “You had a brother. I was sent to kill both of you, but… When it was clear that he was the only one to inherit your demon powers, Satan took him and left you in the snow. I decided to take you in and protect you.”

Yukio’s eyes widen.

Shiro takes the photograph back and slips it into his pocket as he continues, “Your father wasn’t human, Yukio. Suguro’s summon, the King of Air, is your twin brother.”

He takes it about as well as Shiro could have hoped.

“What?” Yukio chokes, blinking in surprise.

“About time, old man,” a bored voice comments as the prince appears at Yukio side, chin resting in the palm of his hand. He fixes Yukio in his bright blue stare and asks, “What will you do now, little brother?”

"No," Yukio retorts, shaking his head.

He straightens up in his seat, ignoring the demon prince who grins beside him.

"No, that isn't possible," Yukio emphatically tells his father, his dad, adopted or not. "I'm not a demon!"

"I understand your concern, but-"

"No, you're not," Rin agrees casually.

Yukio turns to stare at him.

"You're functionally human." Rin shrugs. "Just 'cuz you're one of Satan's sons doesn't mean you have demon powers like me. So don't worry about it!"

Rin beams, but Yukio sits there, stunned.

"Satan's… son," he repeats softly.

Then, to Shiro and Rin's alarm, he lets out a high-pitched laugh, stammers something about going to the bathroom as he stands up, and promptly faints to the floor.

"Oi!"

~+~+~+~

"Hey Bon," Konekomaru says as they sit around the fountain to study. "Isn't that your familiar with Okumura-sensei?"

He points across the lawn at Sensei and a wiley-looking man in familiar traditional robes with golden accents, his blue hair free in a long mane.

"Rin?" Bon exclaims, startled.

The two of them have their heads bent together, speaking in low voices. They're headed toward one of the boys' dormitories, the one sensei lives in. As Rin says something with a serious expression, Sensei does something his students have never seen.

He smiles.

"You're the strangest son of Satan I’ve ever met," Sensei says loudly, stopping in his tracks to turn toward the demon.

Rin grins. He laces his hands behind his head as he continues walking toward the fountain and says something back that none of them can hear. Nonetheless, Sensei's eyes widen in horror and he looks around in a panic. His gaze settles on his students by the fountain.

Swiftly, he follows Rin over to them. He stops at the base of the fountain and clears his throat.

"How much of that did you hear?" he asks sharply, resting his hands behind his back.

Bon bristles. Why was Rin walking around campus talking with their teacher? And what was up with how they acted at the end of the training camp?

"Oh come on," Rin coos, settling down next to Bon and crossing his legs, leaning back to rest on his hand. "It's not that big of a deal, Yuki-chan."

_Yuki-chan? What the hell?_

To Bon' increasing fury and confusion, Sensei blushes.

"It could cost me my career, Rin! If the Vatican finds out-"

"What?" Rin interrupts sharply, fixing him in a sharp stare. "You're only human. It's a shame for them if they can't understand the whims of the heart."

He closes his eyes and tilts his head back, ignoring Sensei's infuriated argument that he makes it sound weird and he should have never stirred up this mess in the first place, but Bon isn't listening.

His heart is pounding in his ears as he watches Rin. The sharp edge of his jaw and the way his soft locks fall around his shoulders, framing his face. The golden earring which dangles from his ear and the sharp upturn of his nose, the soft curve of his upturned lips…

And he's implying he's in a relationship with Okumura-sensei.

Rin cracks open his eyes with a curious hum, fixing Bon in a half-lidded gaze.

"How did you even figure it out, anyway?!" Sensei demands.

Rin looks down at him and the faint smile disappears as he says one name that makes everyone stiffen.

"Neuhaus."

Okumura-sensei's eyes widen in comprehension and he murmurs, "I was his target."

Rin inclines his head.

Bon was wrong. Rin is implying their teacher is _gay_.

"Man, who knew Neuhaus was homophobic," Shima sighs, shaking his head. "That's so lame."

Everyone shifts their surprised stares toward him instead.

"What?" Rin asks, blinking owlishly. "What does that mean?"

Bon stares at him like the idiot he is. To his credit, Rin doesn't even blink.

"Being homophobic means hating or being afraid of people who love the same sex," Konekomaru recites.

"How do you not know that?" Sensei asks him, amazed.

"Demons don't really care about that kind of stuff," he explains with a shrug.

Shima raises his eyebrows and speaks up for the first time. "Does that mean you like double-wielding in more ways than one?"

Bon resists the urge to sigh and roll his eyes, but Rin's face splits into a grin.

"I'm an equal opportunity demon."

He winks at Bon with that _fucking_ grin and Bon can't decide if he wants to kiss him or punch him in the face.

"In any case," Sensei interrupts, pushing his glasses up on his nose, "I'm not gay."

"You're already a teacher and you've never had a girlfriend," Rin retorts, smirking. "That makes you gay."

"It does not!"

"Does too."

"Ugh! How am I related to you?!" Sensei exclaims, and immediately freezes, eyes going wide.

Bon, Shima, and Konekomaru gape at him, speechless.

"Too bad we're only half brothers," Rin replies quickly, smiling. "I would love to see what your domain would be. Tidiness? Yukio, Demon King of OCD?"

Okumura-sensei scowls. Rin just laughs and puts his hands up in surrender.

"You're brothers?" Konekomaru asks in a small voice.

Suddenly everything makes a hell of a lot more sense. And, for some reason, the anxious knot in Bon's stomach finally settles.

"Half-brothers," Sensei corrects with a slight nod. "Our mother was the same."

"I told ya I'm half-human," Rin adds with a sharp-toothed grin.

"Wait, then why was Neuhaus-sensei after you?" Bon asks, frowning.

Yukio isn't smiling anymore. "I’m not entirely sure.”

An awkward silence falls over the group for a moment.

“Anyway!” Rin exclaims, cheerful. He hops down from the fountain and flashes them a grin. “I should get going before your director finds out I’m here and chases me off with a hose. See ya!”

He disappears, and Sensei leaves shortly after.

“What the hell was that about?”

“Who knows,” Bon grumbles, shoving his hands in his pockets. “Let’s get to class.”

~+~+~+~

Bon would like to say he put the thought of Rin out of his head, but unfortunately, that is not the case. He’s thought about him so much, in fact, that his teacher called on him in class and he _almost_ had to ask her to repeat the question. Almost!

When he’s lying awake at night staring at the ceiling with his homework finished and his clothes for the next day set out, Shima’s soft snores filling the room, only then does Bon realize that maybe—crazily—he could be into Rin.

His immediate reaction is horror. Why would he, son of a priest and heir to a temple who has vowed to defeat Satan himself, have a crush on Satan’s son, a Demon King?

It wouldn’t matter, if he stood a chance. Or if Rin weren’t impossibly infuriating, impossibly loyal, or impossibly strong.

If Dad was gonna have a fit about Rin being his son’s _summon_ , finding out Bon has a stupid, ridiculous crush on him might make the old man’s heart give out.

With a soft sight, Bon sits up and slips out of bed. He sneaks out and heads up to the roof. As the cold air whips his hair out of his eyes with the faint scent of the sea, he lifts his chin and shuts his eyes.

The door shuts behind him silently as he steps out onto the roof.

“Relax, brother, I’m being careful,” a familiar voice murmurs. “We begin tomorrow.”

Bon looks over at the last person he wants to see crouched at the roof’s edge, talking on the phone.

With a sigh, Bon sits down next to him. Rin hangs up and looks at him, raising an eyebrow. Bon leans back on his hands to look up at the sky.

“Nice night,” Bon comments. He shoots Rin a glance and asks, “What begins tomorrow, exactly?”

Rin’s expression shifts from curiosity to sadness as he turns away. “War.”

Bon startles.

“Tomorrow, my brothers and I will open a Gehenna gate,” Rin explains softly. “Lucifer and Astaroth will oppose our goal. Father will too, of course, but he’s not much of a threat anymore.”


End file.
